The Missing Inventor Trap: Lessons from Fortress Iron Case

WISECODE Take

In the case No. 2024-2313 decided on April 2, 2026, the U.S. Court of Appeals for the Federal Circuit invalidated two patents of Fortress Iron because a departed Chinese co-inventor, Mr. Huang, could not be located to receive notice. Many business owners mistakenly believe that as long as they hold complete patent ownership, omitting an inventor is a minor administrative error, unaware that the inability to locate an inventor can render the patent void. Under 35 U.S.C. § 256(b), the court ruled that even if the inventor has assigned all rights, they remain a 'party concerned' entitled to notice. Without successful service of notice, the court refused to correct inventorship and declared the patents invalid under § 101. This turns procedural notice into a lethal weapon for patent invalidation. This highlights immense risks for companies relying on cross-border collaboration with high turnover, while companies with stable R&D teams remain unaffected. Zhidian's Patent Portfolio Health Check service helps companies verify inventorship early. In litigation, competitors may weaponize this by searching for unlocatable contributors to sink your patents. We advise: First, explicitly define inventorship disclosure and post-employment cooperation obligations in R&D agreements. Second, thoroughly audit R&D records before filing to ensure actual contributors, like Mr. Huang who proposed the anti-rotation design, are registered immediately rather than corrected post-issuance.